During Watson’s tenure, the agency has expanded workplace safety requirements imposed after the BP disaster, modified separate post-spill drilling safety standards around integrity of offshore wells and related topics, and issued a new “safety culture” policy, among other steps.

Watson, in an email to staff obtained by the Houston Chronicle, said he was leaving with a “heavy heart,” but that he’s taking the “perfect job” that’s well-suited to his background.

Before coming to Interior, Watson, an engineer by training, was the Coast Guard’s director of prevention policy for marine safety, security and stewardship, and has also served as deputy commander of the Coast Guard Atlantic Area Command, among other high-level positions over the years.

At Interior, Watson took a more low-key approach than his predecessor, Michael Bromwich, a former Justice Department official who collided with lawmakers and industry groups in the aftermath of the BP spill and the temporary deepwater drilling moratorium (since lifted) that the department had imposed.